The present invention relates more particularly to a system for providing assistance in piloting that delivers to the crew an image of the external scene that has been processed and optimized for flying at low altitude.
It is difficult to provide the crew of an aircraft with an optimal image of the external scene suitable for enabling the aircraft to fly as close as possible to obstacles so as to carry out a contour flight (for civilian or military purposes), or a tactical flight (for military purposes) under conditions of poor visibility or at night.
The piloting systems that are presently proposed possess numerous limitations and do not make it possible to present dangerous obstacles to the crew of an aircraft in optimum manner.
The present invention lies in the context of providing assistance in enabling an aircraft to avoid obstacles, a field that has given rise to a variety of proposals.
In patent FR-2 780 380, proposals are made to form a pseudo-image from information relating to the topography of the aircraft's surroundings, which information is delivered by an on-board sensor such as a radar or a laser sensor. Analyzing the range associated with each point (pixel) in the pseudo-image enables those points that are closest to the aircraft to be highlighted.
Proposals are made in patent DE-10 065 180, to use information obtained by processing images delivered by one or more cameras on board an aircraft in order to detect the presence of another aircraft and predict is trajectory, in order to avoid a collision between the two aircraft. The image processing includes compressing and adapting contrast.
Other patents propose modifying an image of the external surroundings as a function of information that results from measuring distances:                patent FR 2 712 215 proposes superposing on an image of the external scenery—in the visible or the infrared region of the spectrum—, signs, symbols, or curves of positions that result from processing telemetry data that specifies the tops of dangerous obstacles that have been detected (by telemetry); and        U.S. Pat. No. 6,243,482 proposes mixing the outlines of obstacles determined by processing telemetry data with a basic image sensed by a natural vision system; the processing applied to the telemetry image is high-pass filtering.        
The invention seeks to improve that kind of system for processing images delivered by a (piloting) camera prior to displaying those images.